The present disclosure relates to a fluidized bed for removing carbon dioxide from atmospheric air that is used for conveying particulate materials in particular, dry particulate or powdered hydrated lime for injection into gas desulfurization systems.
It is known that dry hydrated lime can be used for removing sulfur dioxide (SO2) and sulfur trioxide (SO3) from flue gasses issuing from the boilers of fossil fuel burners. The mitigating of SO2 and SO3 emissions by injecting dry powdered hydrated lime sorbent directly into a utility duct work that is seeking to reduce emissions is done by pneumatic conveying systems that convey the hydrated lime to the flue gas ducts or passageways.
Using atmospheric air for the conveying fluid in the pneumatic conveying systems carrying hydrated lime has been found to be less than desirable because any carbon dioxide in the air will react with the hydrated lime (calcium hydroxide-Ca(OH)2) and form calcium carbonate or limestone, (CaCO3). The desirability of reducing carbon dioxide content in an airstream used for pneumatic conveying has been recognized, for example, in U.S. Pat. No. 6,200,543 as well as U.S. Pat. No. 5,678,959.
However, the ability to remove substantially all of the carbon dioxide from ambient air has been lacking in these systems, and it is desirable to have a self-contained, carbon dioxide scrubber for all of the air that is used for pneumatically conveying hydrated lime (calcium hydroxide) to a flue gas scrubbing system.